The present invention relates to electrial plugs and more particularly to switched electrical plugs.
These are plugs which incorporate a switch in the body of the plug itself, so that an appliance which is attached to the plug may be switched on at the plug, without needing to switch on at the appliance, or without having to switch at the socket. Such a plug is clearly useful with a socket having no switch or for use with an adapter when it is not always wanted to switch all the appliances which are connected to the socket by the adapter, which would occur when switching at the socket.
The invention concerns any type of electrical plug. Thus, conventional two- or three-pin plugs, insertable into a scoket by sliding the plug axially with respect to the contact pins of the plug, are contemplated by the invention, as is the type of plug which is pushed into an aperture of a complementary socket, the plug then being rotated to bring its pins into contact with the conductors of the socket.
One problem which is associated with plugs is that arcing tends to occur between the plug contact pins and the socket if the circuit is not broken first by switching off the appliance, socket or plug before inserting or removing the plug from the socket. Arcing causes damage to the plug and socket and is a potential fire hazard.
It is an object of the present invention to provide a switched electrical plug which incorporates safety features, whereby the plug is automatically switched off when the plug is being inserted into, or removed from, a complementary socket.